1. Field of the Invention
The present invention relates to a method and apparatus for providing end-to-end Quality of Service (“QoS”) in Multiple Transport Protocol Environments using permanent or switched virtual circuit connection management. More specifically, the invention provides QoS selection and negotiation procedures among multiple server profiles that allow applications to selectively negotiate connections with servers having desired QoS parameters, regardless of the transport protocols and permanent or switched virtual circuit connection methodologies of the underlying network connection.
2. Related Art
U.S. patent application Ser. No. 09/435,549, filed Nov. 8, 1999, now abandoned, the parent application of the present invention, discloses a method and apparatus for providing quality of service (“QoS”) negotiation procedures for multi-transport protocol access for supporting multi-media applications with QoS assurance. The present invention utilizes the QoS negotiation procedures of the parent application, and adds new QoS selection and negotiation features utilizing Permanent Virtual Circuit (“PVC”) and Switched Virtual Circuit (“SVC”) connection management.
To date, the Internet has grown at a near-exponential rate. Such growth has lead to an accompanying increase in the amount of data transmitted across the Internet, in addition to a general increase in the amount and variety of user applications. For example, diverse multimedia applications that support voice, streaming video, images, and other data types have gained popularity and market demand. However, despite the wonderful successes the Internet has experienced, a means for guaranteeing QoS, connection management, and security for such diverse applications is lacking.
The prevalent communications protocol used by the Internet is Transmission Control Protocol/Internet Protocol (“TCP/IP”). However, because TCP/IP was originally designed to transfer data, it has limited capability in guaranteeing QoS for non-real time data applications. Real-time applications such as voice and video, which require guaranteed QoS and multi-service provisioning, are therefore not adequately supported by TCP/IP. For example, when a user executes real-time applications such as voice or video, such applications may need to be supported with multi-service provisioning and guaranteed QoS which includes bounded delay and delay variance. Such applications may impose significant constraints on delay and/or delay variations. Generally speaking, the user does not sense degradation in the quality of the signal as long as the delay and/or delay variations are bounded.
Asynchronous Transfer Mode (“ATM”) is a widely-used networking technology that guarantees a variety of QoS types for almost every type of traffic characteristic. Because the protocol was explicitly designed to support connection-oriented service and provides various QoS's, it can provide unified transport methods to send data using circuit emulation. In addition, the ATM transport can support real-time voice or video applications while satisfying the QoS requirements for such applications precisely.
However, given a choice between multiple servers connected by ATM links to the service premise equipment (i.e., ATM switches), there should be a method for end-user customer premise equipment (i.e., user workstations) to select between the QoS profiles and services provided by these servers. The present difficulty in the art, however, arises when such servers have varying ATM connection methodologies, thereby giving rise to the need to provide QoS selection and negotiation procedures that can adapt to the varying methodologies, working efficiently and reliably therewith.
Permanent Virtual Circuit (“PVC”) and Switched Virtual Circuit (“SVC”) represent two of the most prevalent connection methodologies for ATM networks currently known in the art. PVC uses pre-established connections that can be configured by an operator. The operator can establish a PVC by setting up a Virtual Path (“VP”) or Virtual Channel (“VC”) between a server and a client machine, either directly or through a series of ATM connections. When VPs or VCs are established, Virtual Path Identifier (“VPI”) or Virtual Circuit Identifier (“VCI”) values become available. If either the VPI or VCI values are provided, a user can connect to a server using a PVC. Such a PVC can be established through multifarious physical interconnect media and protocol combinations, such as Point-to-Point Protocol (“PPP”) over ATM over Digital Subscriber Line (“DSL”). The PVC, therefore, serves as a connection path that ensures QoS for user applications that communicate with the server.
In the SVC arrangement, pre-established connections are not available, thereby precluding the existence of VPI and VCI values. In order to effectuate a connection between a user and a server via an SVC connection, the ATM address of the server is utilized. Such an address may become available when the user normally browses over the Internet. When the user acquires the ATM address of the server, an SVC connection can be then be established. Thus, a connection between a user and a server can occur using either a SVC or a PVC.
The present invention allows a user to connect to a server by allowing the user's applications to utilize either PVC or SVC connections to transmit data to and from the server. In this arrangement, a choice of different QoS server profiles becomes available to the user, thus eliminating the need for ATM signaling in the event that there are multiple servers connected by various permanent links. A variety of end-to-end QoS profiles may be selected, regardless of the multiple transport protocols of the underlying network or the SVC or PVC arrangements of such networks.